Hi all,
I am using PXI 4220 (half bridge type 1) to measure a small strain. And I have some question about the accuracy.
As stated on the Spec of 4220, the "Absolute Accuracy at full range is +-61 uV, when norminal range selected as +-10mV", use the fomular "V0/Vex = GF*strain/2, for half bridge type 1", we get the absolute accuracy presented by strain is about (61uV/5V*2/GF = 12.2u, in which Vex=5V and GF=2). Is this calculation right? If I take into account the noise introduced from the wires and so on, what is the practical accuracy of 4220?
If I need a high accuracy measurement, within 1u for example, then, which of NI's product should I use? 1520? 9237?
Thanks very much!
Haiping
